User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0 Build ID: 20141126041045 Steps to reproduce: I have configured as smtp outgoing server smtp.example.com smtp.example.com resolves to a.a.a.a and b.b.b.b (multi-homed) a.a.a.a is down or not reachable or timeouts i tried to send an email Actual results: thunderbird failed to send the email using a.a.a.a as outgoing mail server Expected results: on failure it should try to send email to b.b.b.b , and in general, if the outgoing server has several different ip's, it should try all of them until it succeeds

Basically bug 52384